FIELD OF THE INVENTION AND DESCRIPTION OF PRIOR ART
This invention relates to improvements in a display system of the type that comprises an array of display units each having a small, thin pivoted vane movable by an electrostatic field between a WRITE and an ERASE position. In the ERASE position the vane lies substantially horizontally and is effectively hidden from view; in the WRITE position it is erect and visible. By selection of a pattern of vanes that are moved from one position to the other the array can be caused to produce a display in the form of a verbal or pictorial message.
Such displays may be black-on-white or white-on-black, or the vanes may be coloured. The display may be illuminated by ambient light and/or artificial light. The light may come from the front or the rear.
Such systems are known, an example thereof being illustrated in U.S. Pat. No. 3,304,549 issued Feb. 14, 1967 to W. R. Aiken (Canadian Pat. No. 776,373 issued Jan. 23, 1968).